NATURAL HISTORY NOTES Toadlets Resulting from Trampling by Domestic Sheep
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I observed the mortality of numerous recently metamorphosed NATURAL HISTORY NOTES toadlets resulting from trampling by domestic sheep. My study area was centered on a 15 ha temporary pond, located within a Instructions for contributors to Natural History Notes appear in Vol- pine/spruce forest. This area was within a grazing allotment that ume 29, Number 1 (March 1998). was grazed by sheep for about a week as they were driven to- wards private land. The pond is an important breeding site for B. CAUDATA boreas but usually dries by late July or early August. Over 20 pairs of B. boreas bred there in 1993 and 1995, but the only suc- AMBYSTOMA CALIFORNIENSE (California Tiger Sala- cessful reproduction was in 1995. Because of the prolonged mander). SURVEY TECHNIQUE. Ambystoma californiense is drought in the area, 1995 may have been the first successful re- generally fossorial during the nonbreeding season and little is production since about 1986. By late July 1995, a large number known of its underground habits. A new technique for locating (1,000's) of newly metamorphosed toadlets had concentrated at and observing these salamanders underground is described herein. the shallow west shore; by 1 August the pond had dried. During Fall 1995, pipeline construction was scheduled to cross On 4 August 1995, 500-1000 sheep were herded to within 150 known A. californiense habitat 10 km SW of Santa Maria, Cali- m of the dried pond. At 0700 h on 5 August, I arrived at the pond fornia, USA. In an attempt to "clear" the pipeline right-of-way and discovered the sheep were being driven into the dried pond prior to construction, a fiber optic scope was utilized to locate A. from the west shore, through the concentration of toadlets and californiense underground. The scope was an Olympus IF11D4- towards the habitat frequented by adult toads. After an hour the 30 with a 3 m probe that could be powered by a car battery or sheep were driven out of the pond through the opposite shore. As with a portable battery. With this scope I was able to locate and a result, an extensive area of riparian vegetation was completely observe a number of juvenile A. californiense within California flattened, and the majority of the toadlets were dead or dying. ground squirrel (Spermophilus beecheyi) and Bona's pocket go- Hundreds were trampled by the sheep and by the end of the day pher (Thomomys bottae) burrows. All salamanders were located hundreds more had desiccated. I checked three telemetered adults at depths of 1.3-2.1 m (length of the probe, not depth under the toads that were located in another part of the pond that was surface). These depths documented only the first salamander ob- trampled by sheep and found they had escaped injury, apparently served in each burrow. Within one burrow, a ground squirrel was by hiding under logs or in rodent burrows. observed in a bed of dried grass and upon its retreat from the Submitted by PAUL E. BARTELT, Herpetology Laboratory, probe, three juvenile A. californiense were observed in the grass Department of Biological Sciences, Campus Box 8007, Idaho below and to the side of the ground squirrel's location. Ambystoma State University, Pocatello, Idaho 83209-8007, USA. Present californiense observed were generally active (possibly due to the address: Department of Biology, Waldorf College, 106 South 6th bright scope light) and were often located along the sides of the Street, Forest City, Iowa 50436, USA. burrows. The scope was effective, although somewhat limited, in locat- californiense. ing A. It was able to negotiate the 90° turns of the BUFO PARACNEMIS (Sapo -boi). DEATH FEIGNING. In rodent burrows; however, two or more sharp turns would cause it tropical anurans, death feigning or thanatosis (Edmunds 1974. to jam in the burrows. The directional head was helpful in guid- Defense in Animals. Longman, New York, 357 pp.) is documented ing the probe around turns, although many burrows were too com- in hylids (Sazima 1974. J. Herpetol. 8:376-377; Duellman and plex or too deep for the 3 m probe. I was able to verify presence, Trueb 1986. Biology of Amphibians. McGraw-Hill, New York. but not absence, of A. californiense within a certain burrow sys- 670 pp.; Azevedo-Ramos 1995. Rev. Bras. Biol. 55:45-47). In tem. the genus Bufo, there is a brief report of such behavior in B. Upon identification of several burrows containing A. ictericus in southeastern Brazil (Haddad and Sazima 1992. In L. californiense, an attempt was made to entice them above ground P. C. Morellato [ed.]. Historia Natural da Serra do Japi: Ecologia for capture and possible relocation. These burrow systems were e Preservacao de uma Area Florestal no Sudeste do Brasil, pp. encircled with silt fencing, pitfall traps were installed inside the 188-211. Editoria da Unicamp/FAPESP, Campinas). Herein we fence, and a water truck was brought in to apply water to the report death feigning in B. paracnemis, a large toad widely dis- enclosed areas. The enclosures (20 m 2) were saturated twice a tributed in South America (Frost 1985. Amphibian Species of the day for two days using a total of 18,925 L of water. One juvenile World. Allen Press, Lawrence, Kansas. 732 pp.). A. californiense was caught in a pit-fall trap the morning after the On 24 February 1997, we found seven B. paracnemis (61-106 second day of watering. Even with this limited success, the ex- mm SVL; 16-115 g) resting under a board in a deforested area periment was discontinued due to the size of the habitat to be near the Mucuri River, Municipality of Mucuri, State of Bahia, crossed and the water required to simulate rain. eastern Brazil. When handled, the two smaller specimens (61, 65 I thank Tom Olson for reviewing this manuscript and for the mm SVL; 16, 22.7 g) exhibited death feigning. The smallest speci- loan of and training on the fiber optic scope. men adopted a typical motionless posture, with its limbs close to Submitted by VINCENT J. SEMONSEN, Essex Environmen- the body and eyes closed (Fig. 1) for 15-20 min. This behavior tal, 1810 Sunset Avenue, Santa Barbara, California 93101, USA. was preceded by secondary defensive mechanisms, observed in all specimens, including attempted escape, inflation of lungs, and ANURA emptying of the bladder. Although the function of death feigning is not well understood, it has been related to the avoidance of BUFO BOREAS (Western Toad). MORTALITY. While con- dead prey by certain predators or to the minimization of prey ducting a study of the movements and habitat use of adult Bufo injury when seized by a predator. (Sazima, op. cit.; Azevedo- boreas in the Targhee National Forest in southeastern Idaho, USA, Ramos, op. cit.). Voucher specimens are deposited in the Colecao 96 Herpetological Review 29(2), 1998 Zoologica da Universidade Federal do Espirito Santo (ZUFES for photography. One male (in Nest 2 below) was attending two 140349-354) and the Museu Nacional do Rio de Janeiro (MNRJ egg masses located within a few centimeters from each other. We 18913). observed this frog switching positions from covering one egg mass to the other. Male parental care has not previously been reported for E. schwartzi. The details of the nests recorded on 10 October were as fol- lows: Nest 1: 12 eggs, white; egg diam 4.6-4.9 mm; located at a height of 180 cm within Tillandsia sp. in a tree. This nest to- gether with the attending male, was transported to the laboratory on Guana Island. All eggs, which were kept at 26-28°C became infested with mold with the exception of one egg that hatched on 21 October. Both the hatchling and the male were deposited in the collection at the Museum of Comparative Zoology, Cambridge, Massachusetts (MCZ 125947-948). Nest 2: Egg mass 1 with 13 eggs, white; egg diam 4.4-4.9 mm; Egg mass 2 with 5 eggs, dis- colored; movement within eggs; egg diam 5.5-8.0 mm; located 40 cm from ground within H. antillana. Nest 3: 5 eggs, discol- ored; movement within eggs; egg diam 5.4-6.1 mm; located 36 cm from ground within H. antillana. Nest 4: 10 eggs, white; egg diam 5.0-5.5 mm; located 30 cm from ground within H. antillana. Nest 5: 10 eggs, discolored; movement within eggs; egg diam Flu. 1. Juvenile Bufo paracnemis feigning death. 8.4-8.8 mm; located 25 cm from ground within H. antillana. We thank Ivan Sazima and Jose Perezx Pombal, Jr. for reading this manuscript and for identification of the toad. CZ thanks the PICDT/CAPES (fellowships grant) and RLT the CNPq (grant 302657/87-8). We dedicate this note in memory of Ada° Jose Cardoso for his contribution to the knowledge of Brazilian anurans. Submitted by CLAUDIO ZAMPROGNO, MARIA DAS GRAcAS F. ZAMPROGNO, and ROGERIO L. TEIXEIRA, Departamento de Biologia, Universidade Federal do Espirito Santo, 29040-090 Vitoria, Espirito Santo, Brazil. ELEUTHERODACTYLUS SCHWARTZI (NCN). REPRO- DUCTION. On 10 October 1996, we observed five nests of the terrestrial frog Eleutherodactylus schwartzi on Great Dog Island, British Virgin Islands, West Indies. To our knowledge, this is the first report of nests of this species, which is endemic to the Brit- ish Virgin Islands. The nests were within separate bromeliads located in a patch of ground bromeliads (Hohenbergia antillana) that were ca. 16 x FIG. 1. Male Eleutherodactylus schwartzi attending two egg masses 13 m. Based on locations of advertisement calls of males after within a bromeliad.